This year's winners successfully steered their companies through one of the most challenging periods in recent times.

India may have improved dramatically in its ease of doing business, but most corporate chieftains in the country will tell you that the last four years have been particularly challenging. They had to deal with two enormous domestic disruptions - the midnight demonetisation in November 2016, followed by the rollout of the Goods and Services Tax (GST) in July 2017.

There were also other issues like the rise in both public sector bank non-performing assets as well as corporate bankruptcies across sectors, which meant that only the best run businesses could access funds at reasonable rates. Most banks turned excessively cautious when it came to corporate loans. In fact, the last three years have seen the decline of some of the biggest names in Indian business because of a host of factors, including debt burden.

Meanwhile, the global situation also turned volatile - the rise of protectionist governments and anti-globalisation sentiment, the Chinese slowdown which led to fears of dumping, and finally the trade war unleashed by President Donald Trump of the US.

There were disruptions across sectors, brought on by the rapid evolution of a number of technologies - loosely dubbed the Fourth Industrial Revolution. This meant that CEOs not only had to keep an eye out for challengers rising from completely new industries but also understand how to use technological advances in artificial intelligence, Big Data, Internet of Things, robotics and 3D printing to keep their businesses from falling behind.

Though our eminent panel of jurors choose the best CEOs for the year, the shortlist is based on the past three years' performance of the top-listed companies with the same CEO at the helm. To make it to the shortlist, the leader needs to have grown revenues and operating profits in good years and bad, and also give over average returns to shareholders. This quantitative exercise allows us to weed out CEOs who may be a flash in the pan.

The top three in every category, therefore, are business leaders who have demonstrated exceptional performance in the medium term. Some of them have, of course, exhibited superb performance over an even longer period. There are others who are gracing our list for the first time.

At first glance, they seem a motley group. But there are some commonalities. They all show great long-term vision and have demonstrated bold decision-making. Finally, they have all adapted to any change thrown their way. Read on.